In general, electric vehicles (EVs) are zero emission vehicles that travel by driving a motor with electrical energy stored in a battery, transmitting the driving force of the motor to wheels through a power transmission apparatus, and rotating the wheels using the driving force transmitted thereto, as opposed to internal combustion engine vehicles. As serious environmental pollution, together with the depletion of petroleum resources, has become a problem for all mankind, development of low or zero emission vehicles has been required.
As environmental problems have become a serious issue, environmentally-friendly vehicles have recently emerged for energy saving and minimization of environmental pollution. Especially, hydrogen-fueled cell vehicles, bio-diesel vehicles, electric vehicles, and the like have been spotlighted as vehicles capable of replacing existing internal combustion engine vehicles.
An electric vehicle may include a battery for storing and supplying electrical energy, a motor for generating a driving force by transforming the electrical energy of the battery into torque, an inverter for controlling the torque of the motor, a charger for charging the battery with electrical energy, a parking mechanism for parking the electric vehicle, and the like.
Electric vehicles may include a battery electric vehicle (BEV), a plug-in hybrid EV (PHEV), a hybrid EV (HEV), and the like. A hybrid EV (HEV) is a type of hybrid vehicle and electric vehicle that combines an internal combustion engine with an electric motor, and is characterized by high fuel economy and high efficiency, compared to a conventional internal combustion engine vehicle. A plug-in hybrid EV (PHEV) is a vehicle designed such that a battery of an HEV is recharged by plugging it into an external source of electric power, and a battery electric vehicle (BEV) is a vehicle driven by only a battery and an electric motor.
Meanwhile, a parking mechanism of an electric vehicle according to the related art may include a parking pawl selectively engaged with or disengaged from a parking gear of a differential gear, and the parking pawl may be configured to be operated by a shift-by-wire (SBW). However, the parking mechanism in the related art has a disadvantage of high manufacturing cost since the parking mechanism is constituted by the SBW, the parking pawl, the parking gear, and the like.
To overcome the above-mentioned problem, the latest electric vehicle has electric parking brakes (EPBs) installed therein, which are controlled by a vehicle control unit, and the EPBs have brake components for frictionally locking wheels of the vehicle, an electric motor for operating the brake components, and the like. However, in a case where a driver depresses an accelerator pedal during parking, the EPBs may malfunction due to an error in the vehicle control unit to transmit motor torque to the driving wheels, thereby causing sudden unintended acceleration of the vehicle.